diff --git a/libsrc/visualization/mvdraw.cpp b/libsrc/visualization/mvdraw.cpp
index 2a9afefd..250eacd6 100644
--- a/libsrc/visualization/mvdraw.cpp
+++ b/libsrc/visualization/mvdraw.cpp
@@ -57,6 +57,13 @@ namespace netgen
       return opengl_text_width;
   }
 
+  void MyOpenGLLines(FlatArray<Point<3>> points)
+  {
+    glBegin(GL_LINES);
+    for (auto p : points)
+      glVertex3dv(&p[0]);
+    glEnd();
+  }
 
   // texture for color decoding
   // GLubyte * VisualScene :: colortexture = NULL;
diff --git a/libsrc/visualization/mvdraw.hpp b/libsrc/visualization/mvdraw.hpp
index c1cf63f8..201572a5 100644
--- a/libsrc/visualization/mvdraw.hpp
+++ b/libsrc/visualization/mvdraw.hpp
@@ -90,6 +90,7 @@ namespace netgen
   NGGUI_API extern void Set_OpenGLText_Callback ( void (*fun) (const char * text), int width );
   NGGUI_API extern VisualScene visual_scene_cross;
   NGGUI_API extern VisualScene *visual_scene;
+  NGGUI_API extern void MyOpenGLLines (FlatArray<Point<3>> points);